Parking Lot Retrofit

Rowan University Bio-Infiltration System

Princeton Hydro was contracted by Rowan University to provide design services for the construction of a stormwater retrofit in one of the University’s main parking areas. The existing parking area was constructed prior to the implementation of current stormwater management requirements. Consequently, the original construction of the parking area did not contain any stormwater flow or water quality control measures. The uncontrolled runoff was creating impacts to existing infrastructure and severe streambank erosion on nearby Mantua Creek. In order to address the runoff volume, peak flow rate, and water quality impacts of the parking area, Princeton Hydro designed a series of bio-infiltration islands to capture and infiltrate incoming stormwater runoff as part of the Mantua Creek Implementation Plan.

Under the previous conditions, the series of stormwater inlets created large areas of nuisance ponding due to significant portions of runoff which bypass existing inlets. The bio-infiltration cells reduce the nuisance ponding and will also improve winter weather driving conditions.

The retrofit system was designed in a manner which does not require major infrastructure modifications. Runoff inflow to the bio-infiltration cells and overflow occurs via a series of curb cuts along each cell. Princeton Hydro designed a custom planting plan which focuses on native vegetation ideally suited for the unique hydrologic conditions expected in the bio-infiltration cells.

The project was constructed in the fall of 2011. The bio-infiltration cells provide groundwater recharge, water quality treatment, and peak flow control. In addition to their functional aspect, the bio-infiltration cells provide an aesthetic improvement to the parking area.